Snap-action switch



July 23, 1963 F. N. ANDERSQN SNAP-ACTION SWITCH Filed 001:. 20, 1961INVENTOR. i250 M/YIVDEKSO/V 3,@8,% Patented July 23, 1963 33%,965SNAP-ACTEGN SWITCH Fred N. Anderson, Highland Park, llh, assignor toCherry Electrical Products Corps, Highland Park, 1th, a corporation ofIllinois Filed Get. 20, 1961, Ser. No. 146,6tl8 4 Qlairns. (Ci. zoo-s7My invention relates to a new and useful improvement in a snap actionswitch and more particularly to a. switch having a movable blade that bymeans of an over-centering device is moved with a snap action into andout of circuit making contact.

A particular object of my invention is in the provision in a snap actionswitch of this character of an actuator that has a positive path totravel, and which engages a tension member at a point immediatelyadjacent to the pivotal connection of the movable switch blade and itssupporting member.

A further object of this invention is in the provision in a snap actionswitch of this character of a movable switch blade that is formed so asto provide a greater contact area with its terminal pivot post thusassuring a greater current conductive connection therewith.

A still further object Of this invention is in the provision in a snapaction switch of this character of a movable blade tensioning member inthe form of a coil spring, wherein the coils of such spring are disposedentirely to one side of the terminal pivot post, with the coils of thespring in the path of the switch actuator. The coil spring, as atensioning member for the movable blade, is provided with an elongatedneck terminating into a hook which by the construction of the movableblade has a positive connection therewith.

Another important object of my invention is in the provision in a switchof this character of an arrangement of parts which properly locate thetension member in a pre-determined position with respect to the movableswitch blade and the switch blade actuator.

Yet another object of my invention is in the provision in a switch ofthis character of a cantilever movable switch blade that will moverelative to -a stationary contact with a rocking motion which willeffect a wiping action between electrical contacts.

Yet another object of my invention is in the provision in a switch ofthis character of an arrangement of parts that is economical inmanufacture, simple in assembling, and positive in its operation.

Other objects will appear hereinafter.

The invention consists in the novel combination and arrangement of partsto be hereinafter described and claimed.

The invention will be best understood by reference to the accompanyingdrawings showing the preferred form of construction, and in which:

FIG. 1 is a perspective view of my improved snap action switch.

FIG. 2 is a side elevational view of my switch with the cover removed.

'FIG. 3 is a side elevational view of the interior surface of the coverfor the snap action switch.

FIG. 4 is aside elevational view of my switch showing the parts thereofin an actuated position.

FIG. 5 is a perspective view of the internal parts of my improved snapaction switch.

FIG. 6 is a detailed sectional view taken on line 2-2 of FIG. 2, and

FIG. 7 is a fragmentary perspective view of a portion of the cover.

This application is a continuation-impart of and constitutes animprovement upon the snap action switch shown, described, and claimed inmy co-pending application Serial No. 125,776, dated July 21, 1961.

My improved snap action switch includes a housing generally shown as at10. This housing is provided with a complementary side cover 11 Withinthe housing 10 there is a hollowed out cavity generally indicated as at12. The side cover 11 is provided with a complementary partial cavityindicated as at 13. Correctly positioned within the cavities Hand 13 ofthe housing to and cover 11 is the switch mechanism of this invention.

The switch mechanism includes a pair of spaced apart fixed contactbearing terminals 14 and 14. These terminals 14 and 14 extend throughslots formed in the end wall 15 of the housing 10. Each of the terminals14 and 14' have their corresponding opposite edges notched as at 16 and17 as viewed in FIG. 5. The notches formed in the one corresponding edgeof each of the terminals 14- and 14 fit into the slots formed in the endwall 15 of the housing 10. The notches 17 formed in the correspondingopposite edges of the terminals 14 and 14' receive the end wall 18 ofthe cover 11. The ends of the terminals 14 and 14 which are positionedwithin the cavities 12 and 13 of the body 10 and cover 11 are generallyT-shaped as at 19. The T-shaped ends 19 of the terminals 14 and :14providing laterally extending lugs 19 which fit into horizontallyaligned recesses 2i and 21 formed in the walls of the cavities 12 and13, respectively. It is thus readily seen that between the T-shaped ends19 and the side notches 16 and 17 the terminals 14 and 14' will becorrectly positioned within the switch casing.

Each of the terminals 14 and 14' provide spaced apart confrontingcontacts 22 and 23. A terminal pivot post 24 is provided as part of theswitch mechanism and it extends into the cavity 12 of the housing 10through the bottom wall 25 thereof. The terminal pivot post 24, like theterminals 14 and 14 has its opposite edges notched as at 26 and 27, withthe notch 26 positioned in a slot 28 formed in the bottom wall 25' ofthe housing 10, and the notch 27 formed to receive the bottom wall 29 ofthe cover 11.

The inner confronting walls of the cavities 12 and 13 are each providedwith aligned recesses 311 and 31 which are adapted to receive oppositelyextending lugs 32 carried by the terminal pivot post 24, only one ofsuch lugs 32 being shown. The end of the terminal pivot post 24 which ispositioned within the casing of the switch is bifurcated to providespaced apart pivot post arms 33 and 34. One face as well as oppositecorresponding edges of each of the posts 33 and 34 are provided withV-notches 35 as seen in FIG. 5.

Formed from a spring material is a substantially flat switch blade 36.The body of the switch Iblade 36 is divided into equal portions by apartially extending narrow slot 37. The free ends of these equalportions of the isody of the switch blade 36 are provided withcorresponding shoulders 38. The arrangement is such that the shoulders38 as well as the ends 39 of the equal portions of the body of themovable switch blade 36 on either side of the slot 37 are positionedinto pivotal contact with the V-notches 35 formed in the faces andopposite sides of the pivot posts 33 and 34.

The switch blade 36 has formed therein a diagonal slot 40 which extendsfrom one longitudinal edge of the blade 36 in the direction of andterminates short of the slot 37. However, the slot 40 terminates at apoint adjacent to and in the plane of the slot 37. By the slot 40 acantilever type blade is formed which has a resilient end 41 whichcarries thereon a contact 42. The switch blade 36 is held in contactwith the pivot posts 33' and 34- under tension by a tension member inthe form of a coil spring 43. One end of the coil spring provides anelongated neck 44 which terminates into a book 45 which extends throughand is in contact with the base of the diagonal slot 40. The oppositeend of the coil spring 43 provides a reversely formed hook member 46which is adapted to be hooked upon a spring pin 47. It should be notedthat when the heretofore described parts are assembled within the casingof the switch the convolutions of the coil spring lie entirely to oneside of the pivot posts 33 and 34 directly in line of a switch actuator48. The long neck A- of the tension member 43 extends between the pivotposts 33 and 34 and lies freely within the confines of the slot 37formed in the blade 36.

The opposite end wall 49 of the body It} is provided with a notched outportion which is of a depth less than the cavity 12 formed in the bodyIt). The base of the notched-out portion 50 is provided with a circularpit 51 in which is seated one end of the spring pin 47. The cover 11adjacent one end 52 thereof is provided with a corresponding alignedrecess 53 into which freely projects the opposite end of the spring pin47 when the cover 11 is mounted on the body It) as shown in FIG. 1.

The end 52 of the cover 11 provides a lateral extension 54 whichprovides a rear wall for the notched-out portion 50 of the end wall 49of the body It) when the cover is mounted thereon. The cover 11 adjacentthe recess 53 inwardly of the lateral extension 54 is provided withspaced apart bosses 55. These bosses 55 project inwardly of thenotched-out portion 5t) and lie above and below the spring pin 47 andmaintain the hook 46 of the tension member 43 on the spring pin 47.

The cover 11 on its inner face adjacent the bosses 55 provides anelongated extending lug 56. This lug 56 is adapted to lie against oneside of the coils of the tension member 43 so as to maintain the same ina predetermined position within the casing of the switch. The lug 56 iselongated so that it will always have a surface in abutment with thecoils of the spring even as the same is moved by the actuator 48 intothe position shown in FIG. 4.

The body in the top wall thereof is provided with a passage 5*? whichcommunicates with the cavity 12. Within the passage 57 is slidablyprojected the stem portion 58 of the switch actuator 48. The actuator 43is formed in a substantially L-shape with the lower corner thereofnotched out as at 59, and with a portion 60 of the base leg thereofextending in a depending plane with respect thereto.

A laterally extending guide 61 is carried by the depending portion 60 asseen in FIG. 5. This guide 61 is adapted to ride in a groove 62. formedin the side wall of the body *10. The L-shaped actuator 58 provides ashoulder 63 which in normal position is in contact with a portion of thetop wall '64 of the body '10 which defines the cavity =12. This shoulder63 prevents outward movement of the actuator 4-8 from within the cavity12 of the body 10.

By reason of the actuator 48 being L-shaped, an offset foot portion 65thereof, will engage the tension spring 43 at a point adjacent thebifurcated ends of the pivot posts 33 and 34 as seen in FIGS. 2 and 4,and thus be laterally distant from the long axis of movement of suchactuator, for a purpose hereinafter explained.

When the actuator 48 moves inwardly of the body 10 in its controlledpath, it will depress the tension member 43 below the point of pivotalconnection between the blade 36 and the pivot posts 33 and 34, creatingincreased tension in the blade 36 causing the same to move with a snapaction into the position shown in FIG. 4 where the contact 42 of theblade 36 engages contact 23 of the fixed terminal member 14. As theblade 35 is of a cantilever configuration the contact 42. will actuallyrock on the contact 22. before the blade 36 moves with a snap actioninto its actuated position.

A positive action of the blade 36 results from the fact that the tensionmember 43 is actuated through the pressure of the foot 65 of the switchactuator 48 engaging a portion of the tension member 43 at a point asclose as possible to the pivotal connection of the blade 36 with thepivot posts 33 and 34, thus reducing the amount of deformation of thespring necessary to actuate the blade. This also has a direct bearing onthe amount of external pressure required to cause movement of theactuator relative to the spring.

In FIG. 3 it will be noted that adjacent the corner of the cover 11defined by the walls 18 and 29 thereof there is formed on the exposedsurface a laterally extending rib: -66. This rib 65 is adapted to sit ina mar- 'ginal channel 67 formed in the confronting exposed surface ofthe body 1h. The marginal rib 6:5 is interrupted by a passage 68 whichreceives the notched out portion 17 of the fixed terminal 14 when thecover is mounted in a closing position upon the body 10.

From the foregoing construction it is apparent that I provided a movableswitch blade 36 which has a greater area of current conductive contactwith the pivot post arms 33 and 34 of the fixed terminal 24. This byreason of the requirement of only a very narrow slot 37 formed in theblade 36 in which is positioned the thin elongated neck 4 of the tensionmember 4-3. This neck 44 also permits the pivot post arms 33 and 34 tobe of a size presenting a greater pivotal contact area with the movableblade 36. The diagonal slot 44 assures proper positioning of the hook 45of the tension member 43 to the blade 36 as well as forming a cantileverend 41 for the movable blade.

By incorporating confronting and cooperating connecting parts on thebody 10 and cover II, -I have provided a switch casing in which theswitch mechanism may be readily and simply assembled. By reversing thehook members 45 and 46 of the tensioning member 43, I have provided apivoting connection between the blade 36 and the tensioning member 43which increases the life of the tensioning member 43 and prevents thesame from transmitting a bending motion on to either end of the tensionmember as.

While I have illustrated and described the preferred form ofconstruction for carrying my invention into effect, this is capable ofvariation and modification without departing from the spirit of theinvention. I, therefore, do not wish to be limited to the precisedetails of construction set forth, but desire to avail myself of suchvariations and modifications as come within the scope of the appendedclaims.

Having thus described my invention, what I claim as new and desire toprotect by Letters Patent is:

1. A snap-action switch housing, having a body normally open at one sideand a cover therefor, with said body and cover providing an interiorcavity containing a snap-acting mechanism including (a) an elongatedcoil spring,

(b) said coil spring having one end connected to a movable switch bladeand its opposite end attached to a supporting means carried by saidhousing,

(6) a supporting means extending transversely between said body and saidcover and upon which one end of said coil spring is hooked,

(d) said housing providing a compartment for said supporting means,

(e) said compartment comprising a notched-out opening formed in one endwall of said body of a depth less than said cavity formed therein,

(f) and means carried by a corresponding end wall of said cover forclosing said notched-out opening and for positioning the hooked end ofsaid coil spring upon said supporting means for maintaining said coilspring in a predetermined longitudinal plane with respect to the movableswitch blade.

2. A snap-action switch housing as defined by claim 1 wherein said meansfor closing said notched-out opening comprises laterally extendingprojections integrally formed on said cover for insertion into saidnotched-out opening on three sides of said supporting means formaintaining said coil spring thereon.

3. A snap-action switch housing as defined by claim 1 wherein saidsupporting means comprises a pin projecting laterally with respect tosaid body and said cover and upon which is hooked one end of said coilspring, one end of said pin centered in said compartment provided bysaid body and having its opposite end positioned centrally with respectto said closing means provided by said cover.

4. A snap-action switch housing, having a body normally open at one sideand a cover therefor, with said body and cover providing an interiorcavity containing a snap-acting mechanism including (a) an elongatedcoil spring,

(b) said coil spring having one end connected to a movable switch bladeand its opposite end attached to a pin carried by said housing,

(0) a pin extending transversely between said body and said cover andupon which one end of said coil spring is hooked,

(d) said housing providing a compartment for said pin,

(e) said compartment comprising a notched-out opening formed in one endwall of said body of a depth less than said cavity formed therein,

(f) and means carried by a corresponding end wall of said cover forclosing said notched-out opening and for positioning the hooked end ofsaid coil spring upon said pin for maintaining said coil spring in apredetermined longitudinal plane with respect to the movable switchblade,

(g) said closing means comprising laterally extending projectionsintegrally formed on said cover for insertion into said notched-outopening on three sides of said pin for maintaining said coil springthereon.

References Cited in the file of this patent UNITED STATES PATENTS

1. A SNAP-ACTION SWITCH HOUSING, HAVING A BODY NORMALLY OPEN AT ONE SIDEAND A COVER THEREOF, WITH SAID BODY AND COVER PROVIDING AN INTERIORCAVITY CONTAINING A SNAP-ACTING MECHANISM INCLUDING (A) AN ELONGATEDCOIL SPRING, (B) SAID COIL SPRING HAVING ONE END CONNECTED TO A MOVABLESWITCH BLADE AND ITS OPPOSITE END ATTACHED TO A SUPPORTING MEANS CARRIEDBY SAID HOUSING, (C) A SUPPORTING MEANS EXTENDING TRANSVERSELY BETWEENSAID BODY AND SAID COVER AND UPON WHICH ONE END OF SAID COIL SPRING ISHOOKED, (D) SAID HOUSING PROVIDING A COMPARTMENT FOR SAID SUPPORTINGMEANS, (E) SAID COMPARTMENT COMPRISING A NOTCHED-OUT OPENING FORMED INONE END WALL OF SAID BODY OF A DEPTH LESS THAN SAID CAVITY FORMEDTHEREIN, (F) AND MEANS CARRIED BY A CORRESPONDING END WALL OF SAID COVERFOR CLOSING SAID NOTCHED-OUT OPENING AND FOR POSITIONING THE HOOKED ENDOF SAID COIL SPRING UPON SAID SUPPORTING MEANS FOR MAINTAINING SAID COILSPRING IN A PREDETERMINED LONGITUDINAL PLANE WITH RESPECT TO THE MOVABLESWITCH BLADE.